The Estrela Mountain Dog, known as C?o da Serra da Estrela, is a large, robust breed originating from Portugal's Serra da Estrela mountains. It features a thick, weather-resistant coat, either long or short. Known for its loyalty, intelligence, and protective instincts, it's an excellent livestock guardian.

The Estrela Mountain Dog is native to the Estrela Mountains, located in the central region of Portugal. This breed is specifically associated with the Serra da Estrela, the highest mountain range in continental Portugal.

The Estrela Mountains are characterized by a Mediterranean climate with cold, wet winters and warm, dry summers. The region features steep, rocky terrain and dense forests, providing a rugged and challenging environment. The area is rich in biodiversity, with a variety of plant species and a diverse range of wildlife.

The Estrela Mountain Dog has traditionally served as a livestock guardian, a role that has shaped its ecological niche. The breed is well-suited to the mountainous terrain and climatic conditions of its native region. It is adapted to protect flocks from predators such as wolves and other threats, utilizing its keen senses, strength, and agility. The Estrela Mountain Dog's thick coat provides insulation against the cold, while its endurance allows it to patrol large areas effectively.